1. Technical Field
The invention relates to methods and materials involved in displaying polypeptide sequences using viruses such as avian leukosis viruses.
2. Background Information
Display technology involves generating libraries of modularly coded biomolecules and screening those biomolecules for particular properties. One feature of display technology is to link a particular phenotype (e.g., a displayed polypeptide) to its genotype (e.g., a nucleic acid encoding the displayed polypeptide) so that the genotypes of selected phenotypes can be rapidly identified. Polypeptide display systems include viral display systems as well as cell-based display systems. Viral and cell-based display systems have the ability to amplify the selected population of displayed polypeptides.
Phage display has been used extensively as a platform for polypeptide display, accommodating a wide-range of polypeptides from small polypeptides to single chain antibodies. For example, phage display libraries have been used to select polypeptides that specifically bind to unique antigens on immobilized polypeptides and to targeted receptors on cultured cells (Li, M., Nat. Biotech., 18:1251–1256 (2000)). In addition, in vivo selection strategies of phage display polypeptide libraries in mice have been developed (Pasqualini and Ruoslahti, Nature, 380:364–366 (1996)). These selection strategies allow cells, organs, and tumors to be studied in their natural environments, a complexity that is difficult to model in vitro. Thus, the power of polypeptide display technology for identifying new therapeutic targets such as targets for cancer treatment both in vitro and in vivo is clear.